1. Field of the Invention
The present invention relates to a nonaqueous electrolyte secondary cell, and more particularly to a nonaqueous electrolyte secondary cell including a positive electrode in which a positive electrode active material layer including positive electrode active material particles is held on a positive electrode collector and a negative electrode in which a negative electrode active material layer including negative electrode active material particles is held on a negative electrode collector.
The present application claims priority to Japanese Patent Application No. 2015-156389 filed on Aug. 6, 2015, the entire contents of which are hereby incorporated by reference.
2. Description of the Related Art
Lithium ion secondary cells, nickel hydride cells, and other nonaqueous electrolyte secondary cells have recently gained importance as power sources to be installed on vehicles and also power sources for personal computers and portable terminals. In particular, lithium ion secondary cells which are lightweight and make it possible to obtain a high energy density have been advantageously used as high-output drive power sources for installation on vehicles.
A typical configuration of a nonaqueous electrolyte secondary cell of this type includes electrodes in which an electrode active material capable of reversibly absorbing and desorbing charge carriers, (for example lithium ions in the case of a lithium ion secondary cell) is formed on an electrode collector. For example, a carbon material such as graphite is an electrode active material (negative electrode active material) for use in a negative electrode. A copper foil is an example of a collector (negative electrode collector) for use in a negative electrode. Japanese Patent Application Publication No. 2013-258392 discloses the conventional technique relating to the negative electrode of this type. Thus, Japanese Patent Application Publication No. 2013-258392 discloses the feature of using as a negative electrode active material a composite carbon material in which the surface of a carbon material forming a core is covered with a carbon black. Japanese Patent Application Publication No. 2013-258392 indicates that an excellent low-temperature characteristic can be realized as a result of covering the carbon material surface with a carbon black.